//
//  CHKeychain.m
//  ENTBoostChat
//
//  Created by zhong zf on 14-8-5.
//  Copyright (c) 2014年 EB. All rights reserved.
//

#import "CHKeychain.h"

#define KEY_USERNAME_PASSWORD  @"com.entboost.chat.usernamepassword"
#define KEY_USERNAME @"com.entboost.chat.username"
#define KEY_PASSWORD @"com.entboost.chat.password"

@implementation CHKeychain

+ (void)saveUserName:(NSString*)userName AndPassword:(NSString*)password
{
    NSMutableDictionary *usernamepasswordKVPairs = [NSMutableDictionary dictionary];
    
    if (userName)
        [usernamepasswordKVPairs setObject:userName forKey:KEY_USERNAME];
    
    if (password)
        [usernamepasswordKVPairs setObject:password forKey:KEY_PASSWORD];
        
    [CHKeychain save:KEY_USERNAME_PASSWORD data:usernamepasswordKVPairs];
}

+ (void)removePassword
{
    [self saveUserName:[self userName] AndPassword:nil];
}

+ (void)removeUserNameAndPassword
{
    [self saveUserName:nil AndPassword:nil];
}

+ (NSString*)userName
{
    NSMutableDictionary *usernamepasswordKVPairs = (NSMutableDictionary *)[CHKeychain load:KEY_USERNAME_PASSWORD];
    return [usernamepasswordKVPairs objectForKey:KEY_USERNAME];
}

+ (NSString*)password
{
    NSMutableDictionary *usernamepasswordKVPairs = (NSMutableDictionary *)[CHKeychain load:KEY_USERNAME_PASSWORD];
    return [usernamepasswordKVPairs objectForKey:KEY_PASSWORD];
}

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (__bridge id)kSecClassGenericPassword,(__bridge id)kSecClass,
            service, (__bridge id)kSecAttrService,
            service, (__bridge id)kSecAttrAccount,
            (__bridge id)kSecAttrAccessibleAfterFirstUnlock,(__bridge id)kSecAttrAccessible,
            nil];
}

+ (void)save:(NSString *)service data:(id)data {
    //Get search dictionary
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Delete old item before add new item
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
    //Add new object to search dictionary(Attention:the data format)
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge id)kSecValueData];
    //Add item to keychain with the search dictionary
    SecItemAdd((__bridge CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    //Since in our simple case we are expecting only a single attribute to be returned (the password) we can set the attribute kSecReturnData to kCFBooleanTrue
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge id)kSecReturnData];
    [keychainQuery setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((__bridge CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    if (keyData)
        CFRelease(keyData);
    return ret;
}

+ (void)del:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
}

@end
